When Opera Theatre of St. Louis suggested Terence Blanchard write a piece for them several years ago, his reaction was, “Wow! I don’t know. I’d never done anything like that before.”

But while the Grammy Award-winning New Orleans trumpeter had never composed an opera, he was no stranger to the art form. His father and other family members were fans, and opera records were played frequently in Blanchard’s home when he was growing up.

So after many years of composing award-winning film scores for such notable directors as Spike Lee and George Lucas, Blanchard took on the challenge. The result, called “Champion,” premiered in St. Louis in 2013. It's also been performed in San Francisco and in Washington’s Kennedy Center.

“Champion” makes its New Orleans Opera Association premiere in Blanchard’s hometown this weekend, with performances Friday night and Sunday afternoon at the Mahalia Jackson Theater.

George Manahan, who conducted the opera’s premiere in St. Louis, will lead the Louisiana Philharmonic Orchestra for both performances. The work — which Manahan describes as a cross between jazz and classical — features a jazz quartet in the orchestra pit.

“Champion” is the two-act story of the late welterweight boxing champion, Emile Griffith, who, in 1962, punched an opponent to death during a championship bout. Taunted about his sexual orientation by Benny “Kid” Paret, Griffith cornered Paret in the ring and knocked him unconscious with a flurry of vicious blows. Paret died of his injuries 10 days later.

The libretto, written by Michael Cristofer, focuses on Griffith’s struggles as a gay man in a macho sport, as well as his lifelong remorse for the death of Paret. The story is told as a flashback by an older Griffith, seeking forgiveness from Paret’s family as he descends into senility.

Blanchard heard Griffith’s saga from a friend, former heavyweight boxing champion Michael Bentt. “I’ve been a boxing fan my whole life, and I was blown away when I heard that story,” Blanchard said.

“So, when I was called to write an opera, the first thing I did was call (longtime musical mentor) Roger Dickerson,” he continued. “I said to him, ‘Hey man, what do I do?’ and he said, ‘It’s all about telling stories.’ When I first became a film composer, Roger had told me ‘You’re gaining experience writing for orchestra for something bigger than this’ and now, all these years later, I could see he was right.”

Composition is complex.

“I start out with the vocal parts," Blanchard said. "And then once we work all that out, I start to work on the orchestration. Each part of it is time-consuming and takes a lot of attention to detail. You have to know the sounds and the ranges of every instrument and at which points to emphasize them.

“So, for me, the fun comes in when you start to combine all of those elements in your own unique way to tell a story,” Blanchard said.

The composer will be in the audience for both performances and will come onstage for curtain calls.

“Terence was terrific to work with,” Manahan said. “The work is very tightly composed and he was always open to suggestion. He wanted it to be the strongest theatrical piece possible.

“So, if a singer had an awkward phrase that was hard for them to sing, he was very willing — on the spot — to change notes and tailor it to that singer,” Manahan said. “With a lot of composers, it’s like pulling teeth if you want to change anything. That’s where Terence was a wonderful exception. I’m looking forward to working with him again.”

Arthur Woodley, who sang the title role in NOOA’s 2013 production of “Noah’s Flood,” sings the title role of the older Griffith. Aubrey Allicock is the Young Emile; Karen Slack is Griffith’s mother, Emelda; Victor Ryan Robinson is Paret; and Robert Orth is Howie Albert, Griffith’s manager.

Carol Rausch leads the New Orleans Opera Chorus, and James Robinson serves as stage director. Dancers from the Marigny Opera Ballet will make the local company’s New Orleans Opera debut.